Ordered organic-organic multilayer growth

Abstract

An ordered multilayer crystalline organic thin film structure is formed by depositing at least two layers of thin film crystalline organic materials successively wherein the at least two thin film layers are selected to have their surface energies within ±50% of each other, and preferably within ±15% of each other, whereby every thin film layer within the multilayer crystalline organic thin film structure exhibit a quasi-epitaxial relationship with the adjacent crystalline organic thin film.

What is claimed is: 
     
       1. A method for forming an ordered multilayer crystalline organic thin film structure, the method comprising:
 depositing at least two layers of thin film crystalline organic materials successively, forming the multilayer crystalline organic thin film structure, 
 wherein surface energies of the at least two layers of thin film crystalline layers are within ±50% of each other, 
 whereby all of the at least two layers of thin film crystalline organic materials within the multilayer crystalline organic thin film structure exhibit a quasi-epitaxial relationship with the adjacent crystalline organic thin film. 
 
     
     
       2. The method of  claim 1 , wherein the at least two layers of thin film crystalline organic materials are single crystal organic materials. 
     
     
       3. The method of  claim 1 , wherein the surface energies of each of the at least two layers of thin film crystalline organic materials are within ±15% of each other. 
     
     
       4. The method of  claim 1 , wherein the at least two layers of thin film crystalline organic materials comprise at least two crystalline organic materials. 
     
     
       5. The method of  claim 4 , wherein the at least two crystalline organic materials comprise donor and acceptor materials and the multilayer crystalline organic thin film structure forms a photoactive structure. 
     
     
       6. The method of  claim 5 , wherein the at least two crystalline organic materials comprise a donor/acceptor material pair of NTCDA and DB-TCNQ, tetracene and pentacene, pentacene and C 60 , or tetracene and C 60 . 
     
     
       7. The method of  claim 4 , wherein the at least two crystalline organic materials are a transport/barrier material and an emissive material and the multilayer crystalline organic thin film structure forms a light emitting structure. 
     
     
       8. The method of  claim 7 , wherein the at least two crystalline organic materials comprise a transport/barrier and emissive material pair of anthracene and tetracene, tetracene and rubrene, or anthracene and rubrene. 
     
     
       9. The method of  claim 1 , wherein one of the at least two layers of thin film crystalline organic materials is a base substrate that weakly interacts with the other of the at least two layers of thin film crystalline organic materials. 
     
     
       10. The method of  claim 1 , wherein one of the at least two layers of thin film crystalline organic materials is a base substrate that structurally templates the other of the at least two layers of thin film crystalline organic materials. 
     
     
       11. The method of  claim 1  further comprising a step of providing a base substrate, wherein the at least two layers of thin film crystalline organic materials are deposited on the base substrate forming the multilayer crystalline organic thin film structure, and
 wherein the base substrate comprises a material that weakly interacts with the thin film crystalline organic layer deposited thereon. 
 
     
     
       12. The method of  claim 1  further comprising providing a base substrate, wherein the at least two layers of thin film crystalline organic materials are deposited on the base substrate forming the multilayer crystalline organic thin film structure, and
 wherein the base substrate comprises a material that structurally templates the thin film crystalline organic layer deposited thereon. 
 
     
     
       13. An organic photosensitive device, comprising:
 a first electrode; 
 a second electrode; and 
 a photoactive region disposed between the first electrode and the second electrode, the photoactive region comprising:
 at least two thin film layers comprising at least two crystalline organic materials forming a multilayer crystalline organic thin film structure, 
 
 wherein one of the at least two crystalline organic materials is a hole conducting material and the other of the at least two crystalline organic materials is an electron conducting material, thereby forming a rectifying junction between the hole conducting material and the electron conducting material within the multilayer crystalline organic thin film structure, and 
 wherein surface energies of the at least two thin film layers are within ±50% of each other, whereby all of the crystalline organic thin film layers within the multilayer crystalline organic thin film structure exhibit a quasi-epitaxial relationship. 
 
     
     
       14. The organic photosensitive device of  claim 13 , wherein the at least two crystalline organic materials are single crystal organic materials. 
     
     
       15. The organic photosensitive device of  claim 13 , wherein the surface energies of the at least two thin film layers are within ±15% of each other. 
     
     
       16. The organic photosensitive device of  claim 13 , wherein the at least two crystalline organic materials comprise NTCDA and DB-TCNQ, tetracene and pentacene, pentacene and C 60  or tetracene and C 60 . 
     
     
       17. The organic photosensitive device of  claim 13 , wherein the device is a photosensitive device and the hole conducting material is a donor material, the electron conducting material is an acceptor material and the two materials form a donor-acceptor heterojunction.